In the minimally invasive robot-assisted telesurgery endoscopic manipulation instruments, such as grippers, needle holders etc., are operated at robot arms. An exemplary scenario is shown in FIG. 11. The robot arms 32 are remotely controlled by the surgeon 34 from an input station 36. Here, the endoscopic instruments 10 are fastened to the robot arms 32 located outside the patient's body and are simultaneously inserted into the patient's body via an incision, for example a trocar 38 in the body cavity of the patient 40. The actual surgery is carried out inside the body. Here, the endoscopic instruments 10 comprise functional instrument tips, such scissors, forceps, needle holders etc. not shown in FIG. 11. In the present patent application, these instrument tips are referred to as functional elements.
Advantageously, this mode of surgery causes a slighter trauma of the patient since merely small incisions in the patient's body are necessary. It is thus desirable to reduce not only the size of the incisions but also their number to keep the trauma of the patient at a low level. Generally, an incision for the instrument 10 of the right hand, an incision for the instrument 10 of the left hand and an incision for the optics 42 (endoscope) are required. Depending on the scenario more or even fewer incisions may be necessary.
During surgery additional material is required inside the body. For example, frequently suture material, namely a surgical needle plus thread but also clamps, pads etc., are required.
In the configuration described above which may include e. g. three incisions in the patient's body such material must be inserted and/or removed via one of these three incisions. If the preparation of an additional incision is to be avoided, at least one of the instruments must be removed from the respective incision.
In the robotic minimally invasive surgery special minimally invasive instruments located at robot arms are used, which, in contrast to manually operated instruments (manual minimally invasive surgery), do not include any handle which the surgeon may grip or via which they can be actuated by the surgeon. The degrees of freedom of the robotic/driven instruments, for example a gripper, are controlled by drives, e. g. electric motors in the instrument or in the robot arms. In the variant stated last the torque of the drives is provided at the robot flange and tapped by the instrument with a coupling and transmitted to the degrees of freedom of the instruments.
Systems for use in the minimally invasive robot-assisted surgery are described in the following publications:    S. Thielman et al. “MICA—A new generation of versatile instruments in robotic surgery”, Proc. IROS, 2010,    R. Devengenzo et al. “Instrument interface of a robotic surgical system”, US 2007/0119274 A1, 2007
If in systems known in the art surgical material, e. g. suture material, has to be inserted into the patient's body during surgery and no additional incision is to be made in the patient's body, the insertion must be carried out via an existing incision. One of the robotic instruments must thus be removed. After uncoupling of the instrument from the robotic system the degrees of freedom of the instrument are either no longer controllable or operable (if the actuation is carried out via a drive in the robot) or only controllable by the surgeon sitting at a remote location (if the instrument comprises its own drive). Depending of the system the degrees of freedom are either blocked or completely free. The exchange of the instruments during surgery is however normally carried out by medical support staff, for example a surgical nurse. Such medial support staff cannot grip the suture material with such an instrument outside the patient's body and then insert it together with the instrument into the patient's body.